Safety-guard for power-presses.



J. WRIGHT. SAFETY GUARD FOR POWER'PRESSES.

APPLICATION FILED JUNE 30, I913.

Patented Oct. 31, 1916.

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UNITED STATES FATE QFFTQ,

JAMES WRIGHT, 0F HAMILTON,

WILLIAM SIMPSON STACEY, OF

ONTARIO, CANADA, ASSIGNOR THREE-EIGHTHS T0 HAMILTON, ONTARIO, CANADA.

SAFETY-GUARD FOR POWER-PRESSES.

Original application filed July 20, 1912, Serial No. 710,640.

Specification of Letters Patent.

Patented Oct. 31, 1916.

Patent No. 1,067,632, dated July 15, 1913.

Divided and this application filed June 30, 1913. Serial No. 776,723.

This invention relates to safety guards for power presses and it has more particular reference to stamping press guards which are adapted to prevent injury to the fingers or hands of the operator.

It is well known that presses of the types referred to are usually fitted with a clutchof any appropriate type-interposed between the source of power and the crank or eccentric or other mechanism actuating the reciprocating tool, and means such as a treadle or foot lever are provided for operating said clutch so as to cause the reciprocatory tool to perform its effective stroke, and vice versa to throw said tool out of action when desired. Various safety guards have been heretofore suggested for use in connection, or in conjunction, with the mechanism for throwing the reciprocatory tool into operation to effectually prevent the said tool being connected to the source of power-upon the operation of the clutch treadle for throwing said tool into action-should the fingers or hands or any part thereof bein position to be crushed or injured by said tool, or in the event of any hand tool or other foreign body being accidentally placed or left in position to be crulshed or touched by said safety guard or too This application is divided from my application which was copending herewith and which resulted in the grant of Patent #1,067,682 dated Julv 15, 1913, and which patent discloses a press of the type referred to and in conjunction with which the guard herein shown and described is adapted to cooperate.

The main object of my invention is to provide a safety guard, which moves or always travels slightly in advance of and with the reciprocating tool, and thereby positively insures the operator being warned of approaching danger.

A further feature of my invention consists in arranging the movement of the protective element proper to synchronize with the operation of the press in contradistinction to devices heretofore constructed which are all brought into the protective position by the movement of the foot lever or treadle prior to the release of the clutch.

Another feature of my invention consists in providing a safety guard the protective element proper whereof is automatically lifted to be on a level with the lower face of the reciprocating tool at the top of its stroke.

Another feature of my invention consists in providing a safety guard with means for releasing the protective element when the reciprocating tool has to move backward up into or away from the lower face of the upper die.

A still further feature of my invention consists in providing the safety guard with an automatic stripper which moves in advance of the punch and which, if it encounters the hand of the operator or some other obstruction trips the safety guard and effectively locks the punch from moving, but which, on the other hand permits the latter to operate if no obstruction is encountered.

Another object of my invention is to provide a safety guard with means whereby the protective device is moved down in advance of the downward movement of the reciprocatory tool and prevents the said reciprocatory tool from being moved down by its operating mechanism when the guard or protective device encounters an obstruction-f0r example the hand or fingers of the operator'-so that as a result the tool is prevented from'moving down if the hand or fingers of the operator have not been re-. moved before the protective device has descended.

With these and other objects in view, as will more fully hereinafter appear, my invention consists in the novel features of construction, combination and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings formand said lock nuts; and

ing a. part of this specification, and more particularly pointed out in the appended claims.

In the accompanying sheet of drawings, Figure 1, is a front elevation of one form of my invention only such parts being shown as are necessary for a clear understanding of the invention. Fig. 2, is a part sectional elevation of the same.

Similar numerals of reference are an ployed to indicate corresponding parts in both figures of the drawings.

The form of my invention illustrated embraces a combined guard and automatic stripper that is actuated by the nornial motion of the press. The stripper 106 is fashioned according to service requirements and is elastically supported relative'to the male died, by means of guide rods 10?, 10?, rigidly secured to said stripper by lock nuts 108, 108. These guide rods 10?, 107, are surrounded by light spiral springs 109, interposed between said stripper and the flange 110, at the lower end of the press plunger Two of the guide rods 10?, 107, are slidable through lugs 111, 111, carried by the plunger 5, and provided at their upper ends with eyes 112, to which are connected the lower ends of chains or cords 113, whose upper ends are similarly connected at 11 1, to levers 115, pivoted at 116, on the ends of a transverse bar a, secured by set screws Z),'to the aforesaid plunger 5. The levers 115, are furnished with holes as shown in order that the points of attachment 11 1, of the chains 113, may be accurately gaged.

117, 117, are trip bars or devices fixed at 118, 118, to the guides 6, 6, and they are disposed in the same vertical plane as the levers 115, 115, in order that the depending parts 119, 119, thereof may cooperate with the ends of said levers 115, when the press plunger is nearing the top of its stroke for the purpose explained.

120,120 are bufier stops fitted with lock nuts 121, for regulating the compression of strong compression springs 122, arranged about said stops between the stripper 106, in order to make proper provision for the stripper 106, to effect its function I recess the heads 123, of said stops 120, into correspondingly shaped holes 12%, formed for the purpose in the underside of the said stripper. It will be clearly understood that the degree of compression of the springs 122, is so regulated and adjusted that the heads 123, are never projected below the underside of the stripper 106, and that the clearance in the recesses or holes 1241, is only sufiicient to allow the said stripper to perform its allotted function. 4

Swingingly pivoted at 125, to a rear extension of the stripper 106, I mount a U-shaped bar 126, provided on one limb with a vertically disposed rack 127, adapted a times to co-act with a toothed quadrant 128, on the inner end of the angularly cra ked oscillatory rod 19, which is pivoted at to a bracket 22* forming an extension of the press plunger. In order that the naped bar 126, may be moved about its at 125, at the requisite times to throw 1 racl; 12-7, into and out of gear with the quat rant 128, 1 revoluhly mount-roller ger bu is capable of movement with relat 1011 thereto, it follows that any movement plu ger during the time that the rack-127 is in mesh with the rack 128 will result in roclqir the rod 19 upon its pivot 22 to cause 5. d rod to stop the press in the manner dc? bed in my application aforesaid which resulted in the grant of Patent #1,067,632.

it is to l e remembered that the parts are shown in their elevated position in Figs. 1 and 2 of the drawing. As soon as the plunger starts to move downwardly and the ends of levers 115 are carried away from the stops 119, the springs 109 immediately act to force the stripper or guard away from guard toward the flange 110 and the the flange 110 and this movement in conunction with the downward movement of the plunger causes the roller 129 to have such movementin the cam slot 131 as to immediately bring the rack 12'? into mesh with rack 128. These racks then travel downwardly together.

If, during the downward movement of the punch or plunger and the stripper, the hand of the operator or other obstruction be encountered, the movement of the stripper toward the flange 110 causesthe rack 12'? to act upon rack 128 to tilt rod 19 andst-op the press in the manner hereinbefore set forth. It is to be noted that in the parent application hereinbefore referred to, the tilting of the rod 19 upon its pivot was utilized to release the press clutch as well as to release the braking element for actually exerting a braking action upon the press, audit is to be understood that the present function for rod 19. That is, the movement of this rod may be utilized to release the clutch to stop the press, or it may be utilized invention contemplates the same to release a braking element to exert a positive braking action upon the press mecha- V. J U. ..i

From the foregoing description and accompanying drawings it will be readily seen that by my invention I provide an extremely effective and reliable device for the purposes set forth, while at the same time in no way interfering with the utility or efficiency of the press.

Obviously my invention may be readily adapted to any type of stamping press or machine having a reciprocatory tool worked or operated by a clutch release mechanism, as all parts are made relatively adjustable, and I wish it clearly understood that I do not confine myself to the specific arrangement and combination of parts illustrated and described, various alterations in their form and the arrangement thereof being possible without in any way departing from the spirit and scope of the invention, and it is intended fully to include all such within the present application, and as limited by the appended claims.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a device of the character described, the combination witha press having a plunger, of a guard member movable with said plunger and arranged to travel in advance thereof, and means for automatically bringing said guard to the level of the lower face of the press plunger when said press plunger is in its raised position.

2. In a device of the character described, the combination with a press plunger, of a guard mechanism carried thereby, a press controlling member, and means actuated by said guard mechanism for moving said press controlling member.

3. In a device of the character described, the combination with a press, having a vertically movable plunger, of a guard, resilient elements disposed between said plunger and said guard, and automatic means for drawing said guard upwardly against the tension of said resilient means when the plunger reaches its upward limit of movement.

4. In a device of the character described, the combination with a press, having a vertically movable plunger, of a guard, resilient elements disposed between said plunger and said guard, automatic means for drawing said guard upwardly against the tension of said resilient means when the plunger reaches its upward limit of movement, said automatic means comprising levers pivoted to the frame of the press, fixed members carried by the press frame, and connections between said pivoted levers and said guard.

5. In a. device of the character described, the combination with an oscillatory press controlling member, of a rack carried thereby, a press having a plunger, a guard arranged to act in conjunction with said plunger, and a rack carried by said guard and arranged to be moved into and out of engagement with the first-named rack.

6. In a device of the character described, the combination with a press having a movable plunger, of a press controlling element the movement of which stops said plunger, a guard which moves in synchronism with the plunger, and connections between said guard and the press controlling element so arranged that the encountering of an obstruction by said guard will result in actuating said press controlling element.

7. In a device of the character described, the combination with a press having a movable plunger, of a press controlling element the movement of which stops said plunger, a combined guard and stripper element mounted for bodily movement with the plunger but capable of movement with relation thereto, connections between said guard and stripper element and the press controlling element so arranged that the encountering of an obstruction by said guard and stripper element will result in actuating said press controlling element and means normally tending to move said guard and stripper element away from said plunger, during which movement it acts as a stripper. Signed at Hamilton, in the county of VVentworth, Province of Ontario, Canada, this 23rd day of June, A. D. 1913.

JAMES WRIGHT. In the presence of ALFRED T. BRAT'roN, GERTIE NICHOLSON.

Copies of this patent may be obtained. for five cents each, by addressing the Commissioner of Patents,- Washington, D. G. 

